Ignore the tomatometer which I think we can all safely says lies somewhat if you look at the list of most of the greatest films. For those who enjoy such slices of generation x nostalgia and the earliest films of Linklater involves clever scriptwriting, with a real biting sense of humour throughout even if the subject matter does become a little serious. Some have called it pretentious, but in all fairness I personally believe that it accurately captures the dynamic of young interaction and confusion amid the responsibility of love. While the final third is perhaps a little flailing, becoming more plot driven (as strange as that probably sounds) the moments of pure interactions make you yearn for a similar kind of dynamic to be existent in your life and really make the film something of a wonderful find. How this hasn't transcended into cult status I'll never know. Plus if in any doubt, the Tarantino cameo is worth an entire film of it's own.
P.s. I believe you shouldn't listen to the reviews made my actual critics on films like this, most are disliked for being too simplistic or not full of plot or spectacle and give it poor reviews because it isn't seen as the kind of bull which will win an Oscar. Most audience reviews give it a truly respectable score, and in such times probably give a much better viewpoint on the film. Probably have just wasted a lot of my time though, no one will read this.